Hello all. I have been posting questions about pontiac rods. I have a set of the TRW 2636 (I think I got that number right, the older TRW pistons with less of a dish), with only 2 hours dyno time. They look great. They need notches. I don't want to deck the block a bunch. If I get some aftermarket Pontiac rods, I will need to spend some money to narrow the big end. I just did a search on hypereutetic pistons, and I read a 2 page thread. PAE has them, with notches, for $270. What opinions can I get on using these pistons? The combo will be; 413ish size cam (A Crane that my buddy Len gave me, same duration as the 413, little more lift), as much compression as I can get away with on 91 octane CA gas(remember, a cam with some overlap), headers, and an SP1 (have not bought the intake). I all ready have a set of worked Al Stg 1 heads and a performer on top of my stock rebuild with a TA212. So, at this point, if I bought the hypers, I would save $$$. Do you all think they will survive comfortably in my engine? I could probably get low $200's on ebay for the TRW's. Thank you very much for the help. John McCarthy
just say no to hyperutectics!! john-dont do it!! i have a bunch of junk engine parts to show for 2 expensive engines i built around those exact pistons you are thinking about. i know len well and he even has the last 6 of them i had over there in his shop. he will tell you how badly they broke apart in my engines. :Smarty:
Zowie Hello Scott, I think I know of your lisence plate frame that says; "Lens parts car" or something? I know your car, I looked at it when it was for sale many times, wishing for a winning lottery ticket. I actually know those 6 pistons, he told me me they came from you. I have not talked to Len about my hyper idea yet, I just thought about all this tonight. If I sink all my $$$ into a new motor and it breaks, I will cry, throw a tantrum, and act like your typical 260lb baby. What do you think on the Pontiac rod idea? Did you read the info that Wes Peters gives out on my "Pontiac rod question." Thanx so much for sharing your experiences.
Don't do it. I am currently rebuilding my engine for my Centurion 455 convertible tow car. Not building it for racing but just for a fun car that I can take a few respectable passes for a land barge. Anyway decided to go with factory replacement cast pistons and used a set of new factory stock Buick rods (never been used). Nothing fancy, Stage 1 heads, tow cam and a good converter. The hypereutetic pistons do not like detonation, they have a very bad habit of cracking. You know just talking about this, (must be the old age settling in) I do have a set of factory 455 pistons never used with the pins and even the rings (don't recommend using the rings), they still have the cosmoline thick oil on them. My rebuilt engine had to be bored .030 so I couldn't use the pistons. They were extra parts from a factory new short block, in which I only needed the block. Block went into the racecar. All the pistons need is a good cleaning. If you are interested PM me with your number. Not looking to make a killing, wouldn't mind helping another Buick guy out. Just make sure your block does not need to be bored. They are factory size 455 pistons. Either way good luck with your project. Rick Martinez
I'm not saying that I would do it again, but I've had the hypereutectic pistons with a 413 cam in one of my motors for years under regular abuse. I just made sure the machine shop knew to keep the piston to wall clearance on the low side. They WILL explode with the kind of clearance that a forged piston requires.
hello All right guys. I am sticking with the forged. This sends me back to my Pontiac rod conundrum. Thanx guys.
I have 6 Hypers with less than 6 runs on them .030 like brand new, what does that tell you the other 2 are either in parts or disinegrated, my first race engine, after an all night stint to get the car ready for it's debut, of course the 87 octance in the tank that was at least a year old didn't help! I'll expempt you all from the rest of the story, RV
i run hypers, no problems yet, but i had the block bored to the proper specs and i dont drive or race my car without the proper octane.
They were in my engine when I bought the car so I kept them and haven't had any problems. Made sure the clearances were on the money. Wayne
Hello, I would get the TRW, [or sealed power same thing,] notched for valves. I have seen way to many of the hypers in a million pieces scattered all through motors. Also if you have some "good" Pontiac rods, not some cast things, [I understand the basic everyday Pontiac rod is weaker than the stock Buick rod.] then go for it. You won't have to shave the block so much to get O deck height. Also if you know of a real good crank shop with the right kind of grinder you can also offset grind the rods for .030 under rodbearings and gain a few more thousands in deck height. I would not do this unless you really know and trust the guy grinding the crank. I have no idea what a pain it would be to balance all this. TomW
